Electrostatic catalysis

ABSTRACT

An electrode having an embedded charge contains a substrate, a first electronic charge trap defined at the interface of a first insulating layer and a second insulating layer; and a first conductive layer disposed on the first electronic charge trap; wherein the first conductive layer contains a conductive material configured to permit an external electric field to penetrate the electrode from the first electronic charge trap; and wherein the first insulating layer is not the same as the second insulating layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.16/330,461, filed on Mar. 5, 2019, now U.S. Pat. No. 10,811,502, issuedon Oct. 20, 2020, and which was filed as a U.S. National PhaseApplication under 35 U.S.C. § 371 of International Application No.PCT/US2017/049617, filed on Aug. 31, 2017, which claims benefit ofpriority to U.S. Provisional Application Ser. No. 62/383,685, filed Sep.6, 2016, the entireties of which are incorporated by reference herein.

BACKGROUND

The present technology relates generally to the field of electrodes.More particularly, the present technology relates to electrodes forelectrostatic catalysis.

SUMMARY

In one aspect, provided herein are electrodes having an embedded chargecontaining a substrate, a first electronic charge trap defined at theinterface of a first insulating layer and a second insulating layer; anda first conductive layer disposed on the first electronic charge trap;wherein the first conductive layer contains a conductive materialconfigured to permit an external electric field to penetrate theelectrode from the first electronic charge trap; and wherein the firstinsulating layer is not the same as the second insulating layer. In someembodiments, the first conductive layer contains monoatomic graphene ormolybdenum disulfide. In some embodiments, the substrate containselemental silicon. In some embodiments, the first insulating layercontains a metal oxide. In some embodiments, the metal oxide containssilicon dioxide. In some embodiments, the second insulating layercontains silicon nitride, titanium dioxide, strontium titanium oxide,zirconium oxide, barium titanium oxide, or any combination of two ormore thereof. In some embodiments, the electrode further contains athird insulating layer disposed adjacent to the second insulating layer,thereby forming a second charge trap at the interface of the second andthird insulating layers, wherein the third insulating layer is not thesame as the second insulating layer. In some embodiments, the electroniccharge trap further contains a floating gate containing a conductor orsemiconductor at the interface between the first and second insulatinglayers. In some embodiments, the floating gate contains a dopedpolysilicon. In some embodiments, the electrode is a cathode. In someembodiments, the electrode is an anode.

In another aspect, provided herein are methods of catalyzing a chemicalreaction including contacting an electrolytic medium with an electrodedescribed herein, wherein the chemical reaction takes place within theelectrolytic medium. In some embodiments, the electrolytic mediumcontains a liquid medium, a solid medium, or a gel medium. In someembodiments, the method further includes generating an electric fieldthrough the interface of the liquid medium and the electrode, whereinthe electric field originates from the electronic charge trap.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a non-limiting example demonstrating how the width andheight of a potential energy barrier is affected by an external electricfield from an embedded charge.

FIG. 2 shows the structure of a non-limiting example of an electrodewith an electronic charge trap.

FIG. 3 shows a non-limiting example demonstrating how the width andheight of a potential energy barrier is reduced to an incoming electron.

FIG. 4 shows a non-limiting example of water electrolysis using anelectrode described herein.

FIG. 5 shows a more detailed view of the electric field aspects of theexample of FIG. 4.

FIG. 6 shows a graph correlating the percent transmission of theelectric field from the embedded charge of an electrode described hereinwith penetration distance through the monoatomic graphene layer.

FIG. 7 shows a detailed view of the electric field aspects of anothernon-limiting example of the use of an electrode described herein.

DETAILED DESCRIPTION

Various embodiments are described hereinafter. It should be noted thatthe specific embodiments are not intended as an exhaustive descriptionor as a limitation to the broader aspects discussed herein. One aspectdescribed in conjunction with a particular embodiment is not necessarilylimited to that embodiment and can be practiced with any otherembodiment(s).

As used herein, “about” will be understood by persons of ordinary skillin the art and will vary to some extent depending upon the context inwhich it is used. If there are uses of the term which are not clear topersons of ordinary skill in the art, given the context in which it isused, “about” will mean up to plus or minus 10% of the particular term.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the elements (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein are merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range, unless otherwise indicated herein, andeach separate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate the embodiments and does not pose alimitation on the scope of the claims unless otherwise stated. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential.

As used herein, “embedded charge” refers to charges trapped at theinterface between two dielectric, or insulating, layers, or to chargestrapped within a floating-gate metal-oxide semiconductor field-effecttransistor (floating-gate MOSFET or FGMOS).

As used herein, an insulating layer of “wide band gap” refers to aninsulating layer having a band gap of over about 6.0 eV.

As used herein, an insulating layer of “low to medium band gap” or“narrow to medium band gap” refers to an insulating layer having a bandgap of about 5.5 eV or less.

Provided herein, in one aspect, are electrodes for electrostaticcatalysis. The electrodes described herein generate a high electricfield from embedded charge within the electrode. The externallygenerated electric field can affect the potential energy barrier of achemical reaction by decreasing the height and width of the energybarrier. In some embodiments, the electrode is used as anelectrically-conducting electrode connectable to a power supply and as asource of a high electric field with no electrical shielding. In someembodiments, the electrode is used in redox reactions.

FIG. 1 illustrates how an external electric field can affect a potentialenergy barrier. Also shown is the hypothetical energy barrier forelectron tunneling, which is the primary process that occurs inelectrochemical reactions where electrons tunnel between an electrodeand the nearest molecule. The sum of the original barrier potential andthe potential generated by the external electric field (due to theembedded charge) provides a “final barrier potential” with a lowerheight and narrowed width compared to the original barrier.

Referring to FIG. 2, in one non-limiting embodiment of an electrode(200) described herein, a 100 nm layer of silicon dioxide (202) isdeposited on an N-type silicon wafer (201). A separate 100 nm siliconnitride layer (203) is deposited on top of the silicon dioxide layer(202), thereby creating an interface (204) with very strongelectron-charge trapping properties between the silicon dioxide andsilicon nitride layers. A monoatomic graphene layer (205) is depositedon top of the silicon nitride layer. Deposition can be conducted bychemical vapor deposition (CVD) or by other techniques such assputtering, evaporation, atomic layer epitaxy, molecular beam epitaxy,or a combination thereof. The graphene layer (205) allows a significantportion of the electric field to pass through since its atomic thicknessis less than its Debye length.

For an electrode having the configuration illustrated in FIG. 2,connection to an electrical power source enables the embedding ofelectrons using Fowler-Nordheim tunneling, wherein electrons aretunneled into the interface (as indicated by the arrows), resulting inthe interface becoming the source of a high electric field. An electrondensity of 3×10¹³ electrons/cm² has been demonstrated. The electricfield may be as high as 30 megavolts/cm or about 0.3 V/Å. The monoatomicgraphene layer exhibits good electrical conductivity, while permittingthe penetration of the electric field generated by the embedded chargeto reach beyond the electrode surface and into the electrolytic medium.In this way, the electric field can lower the potential energy barrierof a chemical reaction taking place within this location of theelectrolytic medium. Another view of how the potential energy barrier isinfluenced by the electric field generated by the embedded charge isshown in FIG. 3. Alternatively, the electrons may be trappedballistically using an electron gun. Such a method would not requirethat the electrode contain a conductive substrate such as silicon, butany substrate could be used to maintain the physical integrity of theelectrode itself.

From the above descriptions of the figures, it is apparent that anexternal electric field can have a definite impact on the reactionenergy barrier, assuming that the external field magnitude is on theorder of the intra-molecular electric field. The details the magnitudeof the external electric field and the reaction energy barrier, ofcourse, depend on the specific reaction under consideration, but theprimary physical mechanism underlying chemical reactions (namely thelocalized molecular-interaction electric fields) can be modified by anexternal electric field. In some cases the reaction barrier might bereduced, while in other cases the barrier might be increased—again, itdepends on the specific chemical reaction.

FIG. 4 illustrates an idealized electrochemical reaction to show theimpact of using an electrode with an embedded charge in the waterelectrolysis reaction. In FIG. 4, the cathode is an electrode having anembedded charge, and the cathode is connected to a monoatomic grapheneconductor such that the molecules just to the right of the graphene willsee a localized electric field pointing to the left, due to the powersupply. Because of the embedded negative (−) charge at the dielectricinterface of our electrode, an ADDITIONAL electric field will beobserved which will ADD to the electric field generated by the powersupply. This additional field will reduce the reaction potential barriercausing the reaction-rate to increase, without a subsequent increase inthe supply voltage.

Researchers have recently shown that monoatomic graphene has anexceptionally high electrical conductivity, substantially higher thaneither copper or silver. So even though it is one atomic layer thick, ithas the ability to carry a substantial current. Serge Luryi (Appl. Phys.Lett., Vol 52, No. 6, 8 Feb. 1988) has shown that in spite of its highelectrical conductivity, monoatomic graphene nevertheless allows asubstantial fraction of the electrical field E (from the embedded chargein our case) to pass through the graphene, due to the quantumcapacitance of the material. Electrostatic Screening is thus negligibleespecially when the electric field extends into the electrolyte over avery short distance (as it is for our electrochemical reaction example).This allows almost all of the electric field from the embedded charge toaffect the reaction rate.

FIG. 5 is a more detailed illustration of the electric field aspects asillustrated in FIG. 4. The power supply voltage generates an electricfield across the electrolyte between the cathode and anode. However, themagnitude of this field is effectively zero within the electrolytebecause of the conducting ions in the electrolyte which shield thisfield. Essentially all of the voltage from the power supply is droppedwithin a very small distance from either electrode which provides afield shown as the short arrows in the figure. This distance is on theorder of several angstroms and effectively creates a double layercapacitor at each electrode. This field changes as the supply voltagechanges. Independently, the field from the embedded charge (shown in thefigure as the long arrows) penetrates the graphene layer and adds to theSupply Voltage generated field giving a net field that is substantiallylarger.

Based on the work by Serge Luryi, we have derived an equation thatpredicts the percentage of the embedded charge generated electric fieldthat penetrates through the graphene. FIG. 6 shows that more than 98percent of the electric field penetrates the graphene into theelectrolyte/electrode interface and is available for reducing thepotential energy barrier to a distance of 500 Å from the graphenesurface. In electrochemical reactions, the typical distance the electricfield extends into the electrolyte is typically less than about 10 Å dueto the high double layer capacitance, Cq, near the electrodes.Accordingly, the curve shows that, essentially, 100% of the electricfield penetrates into the electrolyte/electrode interface region,despite graphene being an exceptionally good electrical conductor. Theelectrode having the embedded charge is configured to provide a strongelectric field (of about 0.3 V/Å) that can reduce the reaction energybarrier of many electrochemical reactions. Because the electrostaticfield approach generates the same reaction-increase that a catalystprovides, the effect is referred to herein as electrostatic catalysis.

A non-limiting example with positive embedded charge at the anode isshown in FIG. 7.

In some embodiments, the electrode having an embedded charge includes asubstrate, a first electronic charge trap defined at the interface of afirst insulating layer and a second insulating layer; and a firstconductive layer disposed on the first electronic charge trap; whereinthe first conductive layer contains a conductive material configured topermit an external electric field to penetrate the electrode from thefirst electronic charge trap. In some embodiments, the electrode furthercontains a third insulating layer located adjacent to the secondinsulating layer, thereby forming a second charge trap at the interfaceof the second insulating layer and the third insulating layer. Infurther embodiments, the second insulating layer and the thirdinsulating layer are not the same.

In some embodiments, the electrode having an embedded charge includes asubstrate, a first electronic charge trap defined at the interface of afirst insulating layer and a second insulating layer; and a firstconductive layer disposed on the first electronic charge trap; whereinthe first conductive layer contains a conductive material configured topermit an external electric field to penetrate the electrode from thefirst electronic charge trap; and wherein the first insulating layer isnot the same as the second insulating layer. In some embodiments, theelectrode further contains a third insulating layer located adjacent tothe second insulating layer, thereby forming a second charge trap at theinterface of the second insulating layer and the third insulating layer.In further embodiments, the second insulating layer and the thirdinsulating layer are not the same.

In some embodiments, the electrode having an embedded charge includes asubstrate, a first electronic charge trap defined at the interface of afirst insulating layer and a second insulating layer; a second chargetrap defined at the interface of the second insulating layer and a thirdinsulating layer; and a first conductive layer disposed on the firstelectronic charge trap; wherein the first conductive layer contains aconductive material configured to permit an external electric field topenetrate the electrode from one or more electronic charge traps.

In some embodiments, the electrode having an embedded charge includes asubstrate, a set of alternating adjacent insulating layers of wide bandgap or narrow to medium band gap, and a conductive layer disposed on theset of alternating adjacent insulating layers; wherein an electroniccharge trap is defined at each interface of an insulating layer of wideband gap and an insulating layer of low to medium band gap; and theconductive layer contains a conductive material configured to permit anexternal electric field to penetrate the electrode from at least oneelectronic charge trap.

In some embodiments, the substrate contains elemental silicon. In someembodiments, the substrate contains N-type silicon.

In some embodiments, the electrode contains one or more electroniccharge traps.

In some embodiments, an electronic charge trap is defined at theinterface of a first insulating layer and a second insulating layer. Insome embodiments, the electronic charge trap further includes a floatinggate containing a conductor or semiconductor at the interface of thefirst and second insulating layers.

In some embodiments, an electronic charge trap is defined at theinterface of each insulating layer of wide band gap and each insulatinglayer of narrow to medium band gap. In some embodiments, the electroniccharge trap further includes a floating gate containing a conductor orsemiconductor at the interface of the insulating layer of wide band gapand the insulating layer of narrow to medium band gap.

In some embodiments, an electronic charge trap is defined at theinterface of each insulating layer of wide band gap and each insulatinglayer of narrow to medium band gap within a set of alternating adjacentinsulating layers of wide band gap or narrow to medium band gap.

In some embodiments, the floating gate contains a doped polysilicon. Afloating gate is capable of holding charges (e.g., electrons) in asimilar manner as the interface between insulating layers of wide bandgap and narrow to medium band gap in the absence of a floating gate. Thedifference between former and the latter is that embedded charges at theinterface cannot generally be removed using an electric field whereascharges in a floating gate can be removed by applying a larger electricfield.

In some embodiments, the set of alternating adjacent insulating layersof wide band gap or narrow to medium band gap contains 2, 3, 4, 5, 6, 7,8, 9, or 10, or more layers. This includes a set of alternating adjacentinsulating layers of wide band gap or narrow to medium band gapcontaining 2, 3, 4, or 5 layers. In some embodiments, the set ofalternating adjacent insulating layers of wide band gap or narrow tomedium band gap contains two insulating layers of wide band gapseparated by an insulating layer of narrow to medium band gap. In someembodiments, the set of alternating adjacent insulating layers of wideband gap or narrow to medium band gap contains two insulating layers ofnarrow to medium band gap separated by an insulating layer of wide gap.In some embodiments, the set of alternating adjacent insulating layersof wide band gap or narrow to medium band gap contains two insulatinglayers of wide band gap and two insulating layers of narrow to mediumband gap. In some embodiments, the set of alternating adjacentinsulating layers of wide band gap or narrow to medium band gap containsthree insulating layers of wide band gap, each separated by aninsulating layer of narrow to medium band gap. In some embodiments, theset of alternating adjacent insulating layers of wide band gap or narrowto medium band gap contains three insulating layers of narrow to mediumband gap, each separated by an insulating layer of wide band gap.

The first insulating layer may include silicon dioxide, calciumfluoride, magnesium fluoride, lithium fluoride, aluminum oxide, or anycombination of two or more thereof. The first insulating layer mayinclude a metal oxide. Illustrative metal oxides include, but are notlimited to, silicon dioxide, aluminum oxide, or a combination thereof.

Insulating layers of wide band gap include, but are not limited to,silicon dioxide, calcium fluoride, magnesium fluoride, lithium fluoride,aluminum oxide, or any combination of two or more thereof. For example,silicon dioxide has band gap of approximately 9 eV and calcium fluoridehas a band gap of approximately 12.1 eV. The insulating layers of wideband gap may all be the same or different. One or more of the insulatinglayers of wide band gap may be the same. One or more of the insulatinglayers of wide band gap may be different.

The second insulating layer may include silicon nitride, titaniumdioxide, strontium titanium oxide, zirconium oxide, barium titaniumoxide, or any combination of two or more thereof.

Insulating layers of low to medium band gap include, but are not limitedto, silicon nitride, titanium dioxide, strontium titanium oxide,zirconium oxide, barium titanium oxide, or any combination of two ormore thereof. For example, silicon nitride has a band gap ofapproximately 5 eV. The insulating layers of low to medium band gap mayall be the same or different. One or more of the insulating layers oflow to medium band gap may be the same. One or more of the insulatinglayers of low to medium band gap may be different.

The third insulating layer may include silicon dioxide, calciumfluoride, magnesium fluoride, lithium fluoride, aluminum oxide, or anycombination of two or more thereof. The third insulating layer mayinclude a metal oxide. Illustrative metal oxides include, but are notlimited to, silicon dioxide, aluminum oxide, or a combination thereof.

In some embodiments, the conductive layer is disposed on the firstelectronic charge trap. In some embodiments, the conductive layer isdisposed on a set of alternating adjacent insulating layers of wide bandgap or narrow to medium band gap. The outer surface of the conductivelayer serves as the outer surface of the electrode itself

The conductive layer may contain a conductive material configured topermit an external electric field to penetrate the electrode from theelectronic charge trap. In some embodiments, the conductive materialcontains monoatomic graphene or molybdenum disulfide.

In some embodiments, the electrode is a cathode. In some embodiments,the electrode is a cathode and the embedded charge is negative. In someembodiments, the electrode is an anode. In some embodiments, theelectrode is an anode and the embedded charge is positive.

Provided herein, in another aspect, are methods of catalyzing a chemicalreaction, wherein the method includes contacting an electrolytic mediumwith an electrode described herein and the chemical reaction takes placewithin the electrolytic medium. In some embodiments, the electrolyticmedium is a liquid medium, a solid medium, or a gel medium. In someembodiments, the method further includes generating an electric fieldthrough the interface of the liquid medium and the electrode, whereinthe electric field originates from the electronic charge trap. In someembodiments, the chemical reaction is a redox reaction.

While certain embodiments have been illustrated and described, it shouldbe understood that changes and modifications can be made therein inaccordance with ordinary skill in the art without departing from thetechnology in its broader aspects as defined in the following claims.

The embodiments, illustratively described herein may suitably bepracticed in the absence of any element or elements, limitation orlimitations, not specifically disclosed herein. Thus, for example, theterms “comprising,” “including,” “containing,” etc. shall be readexpansively and without limitation. Additionally, the terms andexpressions employed herein have been used as terms of description andnot of limitation, and there is no intention in the use of such termsand expressions of excluding any equivalents of the features shown anddescribed or portions thereof, but it is recognized that variousmodifications are possible within the scope of the claimed technology.Additionally, the phrase “consisting essentially of” will be understoodto include those elements specifically recited and those additionalelements that do not materially affect the basic and novelcharacteristics of the claimed technology. The phrase “consisting of”excludes any element not specified.

The present disclosure is not to be limited in terms of the particularembodiments described in this application. Many modifications andvariations can be made without departing from its spirit and scope, aswill be apparent to those skilled in the art. Functionally equivalentmethods and compositions within the scope of the disclosure, in additionto those enumerated herein, will be apparent to those skilled in the artfrom the foregoing descriptions. Such modifications and variations areintended to fall within the scope of the appended claims. The presentdisclosure is to be limited only by the terms of the appended claims,along with the full scope of equivalents to which such claims areentitled. It is also to be understood that the terminology used hereinis for the purpose of describing particular embodiments only, and is notintended to be limiting.

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, particularly in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein canbe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” “greater than,” “less than,” and the like,include the number recited and refer to ranges which can be subsequentlybroken down into subranges as discussed above. Finally, as will beunderstood by one skilled in the art, a range includes each individualmember.

All publications, patent applications, issued patents, and otherdocuments referred to in this specification are herein incorporated byreference as if each individual publication, patent application, issuedpatent, or other document was specifically and individually indicated tobe incorporated by reference in its entirety. Definitions that arecontained in text incorporated by reference are excluded to the extentthat they contradict definitions in this disclosure.

Para. A. An electrode having an embedded charge comprising:

-   a substrate;-   a first electronic charge trap defined at the interface of a first    insulating layer and a second insulating layer; and-   a first conductive layer disposed on the first electronic charge    trap;-   wherein:-   the first conductive layer comprises a conductive material    configured to permit an external electric field to penetrate the    electrode from the first electronic charge trap; and-   wherein the first insulating layer is not the same as the second    insulating layer.

Para. B. The electrode of Para. A, wherein the first conductive layercomprises monoatomic graphene or molybdenum disulfide.

Para. C. The electrode of Para. A or Para. B, wherein the substratecomprises elemental silicon.

Para. D. The electrode of any one of Paras. A-C, wherein the firstinsulating layer comprises a metal oxide.

Para. E. The electrode of Para. D, wherein the metal oxide comprisessilicon dioxide.

Para. F. The electrode of any one of Paras. A-E, wherein the secondinsulating layer comprises silicon nitride, titanium dioxide, strontiumtitanium oxide, zirconium oxide, barium titanium oxide, or anycombination of two or more thereof.

Para. G. The electrode of any one of Paras. A-F, wherein the electrodefurther comprises a third insulating layer disposed adjacent to thesecond insulating layer, thereby forming a second charge trap at theinterface of the second and third insulating layers, wherein the thirdinsulating layer is not the same as the second insulating layer.

Para. H. The electrode of Para. A, wherein the electronic charge trapfurther comprises a floating gate comprising a conductor orsemiconductor at the interface between the first and second insulatinglayers.

Para. I. The electrode of Para. H, wherein the floating gate comprises adoped polysilicon.

Para. J. The electrode of any one of Paras. A-I, wherein the electrodeis a cathode.

Para. K. The electrode of any one of Paras. A-I, wherein the electrodeis an anode.

Para. L. A method of catalyzing a chemical reaction comprisingcontacting an electrolytic medium with an electrode of any one of Paras.A-K, wherein the chemical reaction takes place within the electrolyticmedium.

Para. M. The method of Para. L, wherein the electrolytic mediumcomprises a liquid medium, a solid medium, or a gel medium.

Para. N. The method of Para. L or Para. M, further comprising generatingan electric field through the interface of the liquid medium and theelectrode, wherein the electric field originates from the electroniccharge trap.

Other embodiments are set forth in the following claims.

What is claimed is:
 1. A method of catalyzing a chemical reaction, themethod comprising: contacting an electrolytic medium with an electrode;and generating an electric field through the interface of the liquidmedium and the electrode, wherein the electric field originates from theelectronic charge trap, wherein: the chemical reaction takes placewithin the electrolytic medium; the electrode has an embedded charge,and the electrode comprises: a substrate; a first electronic charge trapdefined at an interface of a first insulating layer and a secondinsulating layer; a first conductive layer disposed on the firstelectronic charge trap; and optionally a third insulating layer disposedadjacent to the second insulating layer, thereby forming a second chargetrap at the interface of the second and third insulating layers; thefirst conductive layer comprises a conductive material configured topermit an external electric field to penetrate the electrode from thefirst electronic charge trap; the first insulating layer is not the sameas the second insulating layer; and the third insulating layer is notthe same as the second insulating layer.
 2. The method of claim 1,wherein the second insulating layer comprises silicon nitride, titaniumdioxide, strontium titanium oxide, zirconium oxide, barium titaniumoxide, or any combination of two or more thereof.
 3. The method of claim1, wherein the electrode further comprises the third insulating layerdisposed adjacent to the second insulating layer.
 4. The method of claim1, wherein the electrolytic medium comprises a liquid medium, a solidmedium, or a gel medium.
 5. The method of claim 1, wherein the firstinsulating layer comprises a metal oxide.
 6. The method of claim 1,wherein the substrate comprises elemental silicon.
 7. The method ofclaim 1, wherein the electrode is a cathode.
 8. The method of claim 1,wherein the electrode is an anode.
 9. The method of claim 1, wherein thefirst conductive layer comprises monoatomic graphene or molybdenumdisulfide.
 10. The method of claim 9, wherein the metal oxide comprisessilicon dioxide.